AFHTTPSessionManager - get unserialized/raw response body (NSData?) - ios

Question

I've subclassed AFHTTPSessionManager according to the recommended best practice for iOS 8 (in place of AFHTTPOperationManager, which I was using before).
I can grab the NSHTTPURLResponse from the task (except that has no body, only headers), and the callback returns the serialized responseObject which is fine.
Sometimes I need to log the response as a string or display it in a text field - there doesn't appear to be a way to do this natively using SessionManager? OperationManager allowed you to reference the raw response as an NSString:
operation.responseString;
I suppose I could stringify the serialized requestObject, but that seems like a lot of unnecessary overhead, and won't help if the response object is invalid JSON.
Here's my subclassed singleton:
#implementation MyAFHTTPSessionManager
+ (instancetype)sharedManager {
static id instance;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
instance = [[self alloc] init];
});
return instance;
}
And then to make a simple GET (which I've added to a block method), I can do:
[[MyAFHTTPSessionManager sharedManager] GET:_url parameters:queryParams success:^(NSURLSessionDataTask *task, id responseObject) {
completion(YES, task, responseObject, nil);
} failure:^(NSURLSessionDataTask *task, NSError *error) {
completion(NO, task, nil, error);
}];

Answer 1

You can accomplish this by creating a custom response serializer that records the data and serializes the response using the standard response serializer, combining both the raw data and parsed object into a custom, compound response object.
#interface ResponseWithRawData : NSObject
#property (nonatomic, retain) NSData *data;
#property (nonatomic, retain) id object;
#end
#interface ResponseSerializerWithRawData : NSObject <AFURLResponseSerialization>
- (instancetype)initWithForwardingSerializer:(id<AFURLResponseSerialization>)forwardingSerializer;
#end
...
#implementation ResponseWithRawData
#end
#interface ResponseSerializerWithRawData ()
#property (nonatomic, retain) forwardingSerializer;
#end
#implementation ResponseSerializerWithRawData
- (instancetype)initWithForwardingSerializer:(id<AFURLResponseSerialization>)forwardingSerializer {
self = [super init];
if (self) {
self.forwardingSerializer = forwardingSerializer;
}
return self;
}
- (id)responseObjectForResponse:(NSURLResponse *)response
data:(NSData *)data
error:(NSError *__autoreleasing *)error {
id object = [self.forwardingSerializer responseObjectForResponse:response data:data error:error];
// TODO: could just log the data here and then return object; so that none of the request handlers have to change
if (*error) {
// TODO: Create a new NSError object and add the data to the "userInfo"
// TODO: OR ignore the error and return the response object with the raw data only
return nil;
} else {
ResponseWithRawData *response = [[ResponseWithRawData alloc] init];
response.data = data;
response.object = object;
return response;
}
}
#end
Then set this serializer on your session manager:
#implementation MyAFHTTPSessionManager
+ (instancetype)sharedManager {
static id instance;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
instance = [[self alloc] init];
instance.responseSerializer = [[ResponseSerializerWithRawData alloc] initWithForwardingSerializer:instance.responseSerializer];
});
return instance;
}
Now in your completion handler you will get an instance of ResponseWithRawData:
[[MyAFHTTPSessionManager sharedManager] GET:_url parameters:queryParams success:^(NSURLSessionDataTask *task, id responseObject) {
ResponseWithRawData *responseWithRawData = responseObject;
NSLog(#"raw data: %#", responseWithRawData.data);
// If UTF8 NSLog(#"raw data: %#", [[NSString alloc] initWithData:responseWithRawData.data encoding:NSUTF8StringEncoding]);
// TODO: do something with parsed object
} failure:^(NSURLSessionDataTask *task, NSError *error) {
}];
I just whipped this up without compiling/testing, so I will leave it to you to debug and fill in the gaps.

Answer 2

You can access the “data” object directly from AFNetworking by using the “AFNetworkingOperationFailingURLResponseDataErrorKey” key so there is no need for subclassing the AFJSONResponseSerializer. You can the serialize the data into a readable dictionary. Here is some sample code to get JSON Data :
NSData *errorData = error.userInfo[AFNetworkingOperationFailingURLResponseDataErrorKey];
NSDictionary *serializedData = [NSJSONSerialization JSONObjectWithData: errorData options:kNilOptions error:nil];
Here is code to Get Status code in Failur block
NSHTTPURLResponse* r = (NSHTTPURLResponse*)task.response;
NSLog( #"success: %d", r.statusCode );